UN chief Antonio Guterres calls for an immediate ceasefire, saying the region's 400,000 residents are living in "hell on Earth".

- 'Another Aleppo' -

On February 22, Russia presses at the United Nations for a negotiated withdrawal of rebel fighters and their families, like the one that saw the government retake full control of Aleppo in December 2016.

On February 24, the U.N. Security Council unanimously adopts a resolution demanding a 30-day ceasefire to allow for aid deliveries and medical evacuations.

But new air strikes and shelling batter the enclave for the following two days.

- Daily 'pause' ordered -

On February 26, Moscow announces President Vladimir Putin has ordered a daily five-hour "humanitarian pause" from February 27 and the opening of protected corridors to allow people to leave.

Hours after the measure is meant to take effect, the United Nations says fighting has continued, making relief operations impossible.

- Noose tightens -

A first attempt at delivering aid to the enclave is made on March 5 but it is cut short due to heavy shelling.

Intense air strikes by the regime and its Russian ally kill 91 civilians on March 7, the Observatory says, reporting at least 60 people suffering from breathing difficulties following strikes on the towns of Sakba and Hammuriyeh.

The Doctors Without Borders (MSF) charity speaks of an acute emergency in the enclave and says 15 of the 20 medical facilities it supports have been hit by air strikes or shelling.

Despite the bombardment, on March 9 food aid is distributed in Douma, the largest town in Eastern Ghouta.

The following day the regime cuts off Douma from the rest of the enclave, managing to split the region into three: Douma and its surroundings in the north, Harasta in the west, and Sakba and Hammuriyeh in the south.

On March 11, it captures the town of Medeira, which lies between the three zones.

The regime sets up shelters and food distribution centers for the hundreds of civilians it has evacuated from newly recaptured areas.

- First medical evacuations -

On Monday, the United States presents a new draft resolution to the U.N. Security Council demanding a 30-day ceasefire. More than 1,000 people, mostly women and children, are in urgent need of medical evacuation, according to the U.N.

On March 13, dozens of civilians including "medical cases" are evacuated.

The following day, dozens more are evacuated while the Observatory says at least 31 civilians are killed in bombardments.

On March 15, a convoy of food aid enters Eastern Ghouta with a third delivery to Douma in 10 days.

- Thousands flee enclave -

The same day, thousands of civilians escape into government-held territory, the largest numbers since the regime assault on the enclave began.

Using a corridor through Hammuriyeh opened by the army after a late-night advance, they flee on foot, in cars and on motorcycles to the government-held checkpoint of Adra.